It is not uncommon for objects to become lost in a surgical cavity during a surgical procedure. To minimize the risk of objects being left in a patient following a procedure, a count is made of objects used during the procedure and if the objects present after a procedure do not match the count a search of the surgical cavity is conducted to locate and retrieve any missing object or objects. Since there normally is a pool of blood in the cavity it is nearly impossible to visually locate any missing object, and especially small objects such as needles and the like. Accordingly, the search and retrieval normally is conducted by a surgeon or other medical professional placing his or her hands in the surgical cavity and searching by feel for the lost object. Large objects such as absorbent pads and the like may be relatively easy to locate and retrieve by this method, but it can be difficult to locate and retrieve smaller objects such as needles and the like. Further, there is substantial risk that the surgeon or other medical professional will be pricked or cut if the object being sought is sharp. Moreover, the cavity itself, or parts of the cavity, may be relatively small and difficult to access with the hands or fingers. This can be especially true in neurosurgical procedures where the surgical cavity is relatively small, and there are small crevices or spaces where an object may be located. If the items used during a surgical procedure cannot all be accounted for after the procedure, an X-ray and/or further surgical procedure may be required in order to locate and retrieve a missing item.
Various devices have been developed in the prior art for locating and/or retrieving metallic objects, i.e., objects made of a magnetic or magnetizable material, in body tissue and/or body cavities, including devices developed for use during a surgical procedure. Exemplary of such devices are those disclosed in U.S. Pat. Nos. 1,726,349, 2,321,355, 2,517,325, 2,706,979 and 4,657,020.
U.S. Pat. No. 1,726,349 to Hartsough discloses a rigid magnetic probe that is about the size of a lead pencil (16.5 cm long and 0.682 sq cm in cross section) for inserting in and moving along a body cavity or a wound to attract and retrieve metal objects. Because of its straight and rigid structure this device may be difficult to position in portions of a body cavity.
U.S. Pat. No. 2,321,355 to Berman discloses a relatively complex and expensive apparatus that uses an electromagnet for locating metal objects in body tissue. This apparatus locates the object but does not retrieve it. Moreover, because of its size it can not be easily placed in small cavities and crevices.
U.S. Pat. No. 2,517,325 to Lamb discloses a probe that incorporates a permanent magnet that may be moved into and out of a sheath to increase or reduce the magnetic field so that a metal object can first be oriented before it is attracted to the magnet and removed from the tissue. It is intended for use in retrieving magnetic splinters from the eye or skin of a patient, but is said to also be useful for removing metal splinters from food or electrical instruments.
U.S. Pat. No. 2,706,979 to Wallace discloses an electromagnetic surgical instrument for removing magnetic objects from body passages or cavities. It is a relatively complex and expensive rigid structure in the nature of a probe, and the magnetic field may be varied to enable manipulation of the object before it is removed, thereby preventing trauma to body tissue that might be caused by a sharp object.
U.S. Pat. No. 4,657,020 to Lifton discloses a permanent magnet on the end of an endoscope, with a shield that closes around a sharp object attracted to the magnet to prevent trauma to body tissue when the object is withdrawn from a body cavity. This device is designed and intended for insertion through a relatively large human body tract such as the gastrointestinal tract for retrieving objects that may have been swallowed by the patient.
The foregoing devices are relatively expensive and are intended for re-use.
Other, more simple and less expensive devices are known in the prior art wherein a magnet is carried on the end of a flexible tether for picking up articles made of a magnetic material. Exemplary of such devices are those disclosed in U.S. Pat. Nos. 1,212,870 and 2,623,774.
U.S. Pat. No. 1,212,870 to Zolper discloses a magnetic retrieval tool on a string. The magnet in this patent is a flat, rectangular plate with the string attached to the middle of the plate, and is intended to be suspended from the middle and slid along a floor surface to pick up and lift pins, needles and the like that have been dropped.
U.S. Pat. No. 2,623,774 to Hubbard discloses a toy hoist having a permanent magnet carried on the end of a string for picking up magnetic articles. The magnet is retractable through a tubular housing for dislodging the magnetic article from the magnet.
The foregoing devices are not designed or intended for use in a surgical environment to retrieve magnetic objects lost in a surgical cavity during a surgical procedure.
Accordingly, it would be desirable to have a simple and inexpensive surgical magnetic retrieval tool that can access small and hard to reach areas of a surgical cavity, wherein a small permanent magnet is affixed to the end of a flexible tether so that the magnet can be dropped into the surgical cavity and then pulled through it to attract and remove magnetic objects lost in the cavity during a surgical procedure.